Ice conditions at Sam Charley Slough - Mid study site Ice conditions at this study site midway down Sam Charley Slough on the south side have been observed to vary greatly throughout the winter. It is also not consistent from year to year. Process Observed: Open WaterGroundwater Upwelling Date Process Observed: Saturday, October 1, 2011 to Monday, April 30, 2012 Galleries: Sam Charley Slough - Mid Gallery